<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h1>我是b页面</h1>
    
    <button>点击我回退到上一个历史记录</button>
    <button>点击我跳转到c页面</button>
    <script>
        var btn = document.querySelector("button");
        btn.onclick = function(){
            // 回退到上一个历史记录；
            window.history.back();
        }

        var btn2 = document.querySelectorAll("button")[1];
        btn2.onclick = function(){
            window.location.href = "c.html";
        }



    </script>
</body>

</html>